DRUG CALCULATION
S.Y.JASMINE
WARD INCHARGE
INTRODUCTION
Calculate drug dose correctly is on
essential skill to prevent and reduce
medication error
1.INJ.ADRENALINE
Available strength(1ml=1mg)
Formula:
Mcg x Kg x min
_________________
Strength
________x1000 (1000 =converting mg to mcg)
Dilution
Example::(If strength is 6mg)start Inj. Adrenaline 0.1mcg/Kg/Min
= 0.1x60 x 60 = 0.1x60x60x50
6 x 1000 6x1000
50
= 18000
6000
= 3ml/hr(0.1mcg/hr)
2.INJ.NOR ADRENALINE
Available Strength(1ml=2mg)
Formula:
Mcg x Kg x min
strength X 1000 ( 1000 – Converting mg to mcg )
dilution
Example::(If strength is 6mg)start Inj. Nor Adrenaline 0.2mcg /Kg/Min
0.2X60X60x50
= 6X1000
36= 6ml/hr(0.2mcgs/hr)
6
3.INJ.DOPAMINE
Available Strength( 1 AMP = 5 ML=200 MG)
Average adult weight =60 kg
Formula:
Mcg x kg x mins
Strength x 1000
Dilution
Example:(If strength is 400mg) (start injection dopamine 10mcgxkgxmin)
=10X60X60X50
400x1000
= 36x5
4
= 180
4
= 4.5ml/hr(10mcgs/hr)
4.INJ.DOBUTAMINE
Available Strength(5ml=250mg)
Formula:
Mcg x mins x wt
Strength x 1000
Dilution
Example:(If strength is 500mg(double strength)
( start injection Dobutamine 5mcg X kg X min)
=5X60X60X50
500x1000
= 900000
500000
= 1.8ml/hr(5mcgs/hr)
5.Inj.Amiodarone/cardarone
Available Strength(1ml=150mg)
Formula:
Mg x mins
Strength
Dilution
Example:(If strength is 900mg)( 6 amp )
start inj. Amiodarone 1 mg x min X 6 hrs followed by 0.5mg/min X
18 hrs
1mg x 60
900 =1x60x50 =30
50 900 9
=3.3 ml/hrx 6hrs (followed by 1.7ml/hr x18hrs)
6.INJ.Nitroglycerine(NTG)
Available Strength(1amp (5ml)=25mg)
Formula:
Mcg x mins
Strength x 1000
Dilution
Example:(If strength is 50mg) (start Inj.NTG 10 mcg /min)
=10X60X50
50x1000
= 30000
50000
= 0.6ml/hr(10mcg/hr)
7.INJ.SOMATOSTATIN
Available Strength(1ml=3mg)
Formula:
Mcg x dilution
Strength
Example:(If strength is 3mg) start Inj. Somatostatin 250 mcg / hrs
= 250x50
3x1000
( 1000-coverting mg to mc )
= 25x5
30
= 4.1ml/hr
8.Inj.Fentanyl
Available Strength(2ml=100mcgs/10ml=500mcgs)
Formula:
Desired dosexQuantity
drug concentration
Example: (start Inj. Fentanyl 50mcg/hr)
=50x50
500
= 2500
500
= 5ml/hr(50mcgs/hr)
9.INJ.LASIX
Available strength 1 ml =10 mg
1 amp =40 mg (4 ml)
FORMULA:
Desired dose xQuantity
drug concentration
Example: Inj. Lasix concentration is 20 mg
start 1 mg /hr
= 1x20(20-quantity of the
volume in dilution )
20
=1 ml/hr
10.INJ.PANTOPRAZOLE
Available strength 1 Vial =40 mg
FORMULA:
Desired dose xQuantity
drug concentration
Example: Inj. Pan concentration is 80 mg
start 8mg /hr = 8x50(50-quantity of volume in
dilution )
80
=5ml/hr
11.INJ.VASOPRESSIN
Inj.vasopressin = 1 ml = 20 units
FORMULA:
Desired dose xminutes
drug concentration
Example:(If strength 20units) start Inj. Vasopressin
0.04units /min
=0.04x60
1
=2.4ml/hrs
12.INJ.HEPARIN
Available strength 1 Vial =25000units
25000units will be diluted in 45ml of 5%
dextrose
or 45ml of NS. 1ml=500units
IV FLUID CALCUTION
FORMULA:
(NO OF PINTS) X (DROP FACTOR)
= _________________________
NO OF HOURS X 60 MINTS
EXAMPLE:
500ML X 20
= _______________________
5 HOURS X 60 Min
=100ml /hour
= 33 drops/mins
